A great thing about some VPI models is the interchangeability and upgrade options of the turntable’s components/parts. For instance, the HW-19 came with it’s motor mounted on the table’s wooden base, but VPI later offered a 9 lb. free-standing motor pod (the SAMA), which may be used in place of the stock motor, placed inside the base. Removing the motor from the base minimizes the transfer of vibrations from the former to the latter
Then there is the interchangeability of platters and bearing assemblies. The HW-19 Mk.I through Mk.III came with a very nice 11.5", 10 lb platter and 1" diameter bearing assembly made of aluminum (with a stainless steel spindle and platter support platform, the spindle threaded on it’s top end for use with the included record clamp). The platter is a 1" thick slab of black Delrin (often incorrectly described as acrylic), with a thin disc of lead glued onto it’s underside and covered in cork. For the HW-19 Mk. IV, VPI increased the platter thickness to 1.5 inches (weight unknown to me). The combination of the Delrin platter and dedicated clamp gave me the feeling that the needs of LP playback---in terms of vinyl resonances---had finally been successfully addressed and met.
For the Aries, VPI introduced a new platter and bearing (used through the Aries Mk. IV, as well as the TNT Mk.I through Mk.IV). The platter is comprised of two sections: a bottom section of 7/8" thick aluminum, with the cork-covered lead disc of the HW-19 remaining. Glued and bolted onto that aluminum section is a top section of 5/8" thick Delrin, the total platter measuring 1.25" thick and weighing 15 lbs. The bearing well is machined stainless steel, as with the HW-19 1" in diameter. But unlike the aluminum HW-19 bearing well---which is secured to the table’s floating top plate with bolts, the well of the Aries is threaded, the threads used in conjunction with a nut to secure the well to the table’s top plate.
As the bearing wells of both the HW-19 and the Aries are 1" in diameter, an easy HW-19 upgrade is to replace it’s stock platter and bearing assembly with those of the Aries. That’s why you occasionally see the platter and bearing assembly from an HW-19 for sale, as well (no pun intended) as Aries Mk.I-Mk.IV/TNT Mk.I-MK.IV platter/bearing wanted ads.
Then there is the ultimate upgrade path for both the HW-19 (all versions) and Aries Mk.I through Mk. IV: the replacement of the stock platter with that of the TNT Mk.V. The TNT MK. V platter is a real beaut: a bottom section of 5/8" thick stainless steel (with no lead layer), topped with a 7/8" section of black Delrin, the whole platter measuring 1.5" thick and weighing about 21.5 lbs. This platter is considered by many VPI enthusiasts as the best platter the company ever made. I’m one of those enthusiasts.